Blood Clotting Proteins - Factor
There are 13 blood clotting proteins (coagulation factor) found in the blood. They are designated by Roman Numerals I through XIII. When a blood vessel is damaged, these clotting factors are switched on in a certain order (Blood Clotting Cascade) [link to coagulation page] and work to form a clot. Specifically, these 13 factors normally combine to a clot.
If one factor is missing or present at low levels, this causes hemophilia and other blood clotting problems and a proper clot will not form.
The two most common factor deficiencies are: factor 8 (or factor VIII) deficiency and factor 9 (or factor IX) deficiency. The most common, affecting 80% of the hemophilia population - those with hemophilia A - is factor VIII. When these blood clotting proteins aren't present is not easily stopped.
This factor is so important to the treatment of hemophilia, that instead of saying they have "hemophilia A or B," most people say they are "Factor VIII" or "Factor IX" to identify their condition.
Treatment with Blood Clotting Proteins
Today, many people in the United States infuse blood clotting factor on a "prophy" basis - every other day or so as a preventative measure. This allows them to live a somewhat "normal" life and almost eliminates the worry of spontaneous muscle or joint bleeds.
After an injury, though, daily infusions may be required by your doctor. The factor goes right to work to help form a clot and stop the bleeding.
Recombinant DNA technology
There are many types of factor concentrates available for replacement therapy. Recognized and safe treatment for both hemophilia A and B is a Factor VIII (or Factor IX) concentrate that is made using recombinant dna technology. These recombinant factors are made by inserting the DNA encoding the human protein into mammalian cells grown in culture. They are purified and processed and are non-plasma derived products.
The FDA announced the licensing of the first recombinant DNA-derived clotting factor for use in people with hemophilia A in a press release dated December 10th of 1992. It mentions that the Antihemophilic factor (recombinant) is produced by Chinese hamster ovary cells that have been modified by recombinant DNA technology to introduce the gene for human factor VIII and express factor VIII. The antihemophilic factor (recombinant) is highly purified by several steps involving biotechnology processes. You can read the rest of the press release about recombinant DNA technology here.
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